


Rectifying Past Mistakes

by afteriwake



Category: Sherlock (TV)
Genre: Alternate Universe - Canon Divergence, BAMF Mary, Canon Rewrite, Dangerous Games, Divorced Mary, Divorced Sherlock, F/M, Getting Back Together, Holmes Brothers, Making up for lost time, Mary's Past, Mycroft Being Mycroft, Mycroft's Meddling, No Mary Morstan/John Watson, POV Sherlock Holmes, Past Sherlock Holmes/Mary Morstan, Post-Divorce, Post-Reichenbach, Reconciliation, Relationship History, Reunions, Season/Series 03, Secrets, Sherlock Has Secrets, Sherlock Holmes & John Watson Friendship, Sherlock Holmes Has Feelings, Sherlock Holmes Has a Heart, Sherlock Holmes Returns after Reichenbach, Sherlock Series 4 Spoilers, Sherlock's Heart, Sherlock's Past, Sherlock-centric, Spies & Secret Agents, working together
Language: English
Status: In-Progress
Published: 2016-04-02
Updated: 2017-08-16
Packaged: 2018-05-30 18:39:44
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 5
Words: 4,975
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6435856
Author URL: https://archiveofourown.org/users/afteriwake/pseuds/afteriwake
Summary: <blockquote class="userstuff">
              <p>When Mycroft gets Sherlock out of Serbia, he drops a bombshell on him he isn't <i>quite</i> prepared for: after years of being gone out of his life, Sherlock's ex-wife Elizabeth has reappeared, under the name Mary Morstan. While he was off taking care of Moriarty's mess she was protecting those he cared about and helping his brother, for reasons, he finds, that she is keeping close to the vest. But when they're forced to stay in close quarters at Baker Street both secrets and old wounds come to light and, perhaps, things might turn out for the best after all.</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

  * For [melody1987](https://archiveofourown.org/users/melody1987/gifts), [](https://archiveofourown.org/gifts).



> So a very long time ago I was asked by **Marylocked** " _Hey can you write a Marylock Au in which Sherlock and Mary are married before ASiP?_ " We went into some more details and decided that John would have known around "The Reichenbach Fall" (though for the purposes of the first chapter, Mycroft is not aware he knows) and there would be no Warstan in the series and it would lead to an eventual Sherlock/Mary reconciliation. And then it just kind of sat there for a while because I hadn't written this ship before, even after **melody1987** claimed it in a prompt claim, until finally two days ago my mother asked me to write a Sherlock/Mary fic and so I decided "Okay, I'll do it." And thus, here it is. I hope you all enjoy.

He was not in the mood for surprises, but he could tell his _dear_ older brother had one. 

Wonderful.

They had made it to a safe house in Hungary, driving nearly all night to get to Mongolia from Lake Baikal and then flying nearly immediately upon their arrival to Budapest, and all he wanted to do was sleep. Mycroft had stayed nearly silent the entire trip, and he had tried to sleep, but he knew his brother was simply waiting and that had made him wary of succumbing to his exhaustion. Mycroft was probably quite miffed about the fact he had to leave the comfort of his home in London to come rescue him. Not that he’d had to, to be quite honest; he’d had it all handled quite well. 

So maybe Mycroft hadn’t come to rescue him. Perhaps he had another motive. And if it was something he hadn’t bothered to mention during their five thousand kilometer trip it was probably something he wanted to drop on him like a bombshell, just for the sheer pleasure of watching whatever emotions crossed his face at the news.

Well, he wasn’t going to give his brother the satisfaction.

Someone had prepared food for them, he realized as they stepped inside. He could smell goulash, for a start. Potato and egg casserole as well. Perhaps stuffed cabbage rolls? And fresh bread as well. He felt his stomach grumble at the assault of delicious smells. It had been a long time since he had eaten well; having been running around the wastelands of Serbia having to scrounge for what he could to supplement what few supplies he’d managed to bring with him when he’d left Khazakhstan at that time of year had meant lean meals. He would have to try very hard not to stuff his face.

He saw Mycroft’s PA standing near the stove, checking a pot. “Just in time,” she said. “The goulash is ready, and the rest can come out of the oven shortly. But I think a bowl each should be a good starter.”

“Thank you,” Mycroft said with a nod. He had rid himself of the garish hat long before they left Serbia but kept the coat. With as much as it cost he had expected nothing less. At least he had gotten him out of the rags he had been in. Not in clothing remotely close to the quality he had been used to but it was a step up from what he had been wearing. She gestured to the table near the stove and the two of them sat down, and after a moment she brought them each a bowl of the stew and a spoon. Sherlock gripped the spoon tightly and then slowly spooned himself a spoonful of the goulash before taking a bite. It was quite excellent.

“Do you want bread?” Anthea asked him. He nodded, and she went to the counter and used a knife to cut him a thick slice, then another. She took the bread and put the slices on a plate, then took that and a small plate of butter with a knife on it to the table and set it in front of Sherlock. He picked up the knife and put some butter on the bread before dipping it into the goulash and taking a bite.

Mycroft waited until he was about to swallow before he spoke to him. “Your ex-wife is in London.”

Sherlock nearly choked on his food. Of all the things he had expected his brother to say, _that_ had certainly not been among them. He had tried to find her for years, but she had hidden herself well. It was as though she was more ghost than person, to be quite honest. And just like a ghost she haunted his mind, usually never being far from his thoughts. To the world at large he _had_ no prior relationships to speak of, and _certainly_ no ex-wife. When asked about why he wore a wedding band, he said it was his grandfather’s, a lie that slipped out easily. Only one man, only John, knew the truth. But Elizabeth Christine Fisher had been…enthralling, for lack of a better term. She had been everything he ever could have wanted, everything he ever could have needed.

And he had let her slip away.

No.

He had let the man sitting in front of him rip her away from him. He needed to remember that.

He did his best to recover and keep a neutural expression. “The CIA let her off their tight leash?” he asked, tearing off more bread to dip into his goulash.

“Quite a few years ago, apparently,” he said.

“Did you know?” Sherlock asked quietly.

“No, I did not,” he said. “She’s been back on British soil since roughly 2009, when a certain consulting criminal put word out that he needed the best of the best for a project.” He had another bite of his goulash. “She was more than willing to throw her lot with him until a certain night at a certain pool, when she stared down the sight of a gun and who did she see but her ex-husband? That was when she realized that James Moriarty had plans to go after you and she wanted nothing to do with them, and so she began to play her own game.”

Sherlock scoffed silently. “And just what was that?”

“She kept her ears open and fed information to the right people when she could to keep you safe,” he said quietly. “Passed it on to my handlers anonymously. After your apparent death, she began to speak to me directly. She’s been quite…useful.”

Sherlock looked down at his bowl and said nothing. He didn’t believe that Elizabeth cared. Not after the way things ended. Not after what he had done when she had been driven off. Not after what _she_ had done. She had to hate him, hate the very sight of him. “And I suppose you’re telling me she played personal bodyguard to the people I left behind in London?” he asked.

“She goes by Mary Morstan now, she works at John’s surgery as a nurse, and she’s insinuated herself in his life and the lives of the others in your circle of…goldfish,” he said.

Sherlock scowled slightly at Mycroft’s term for his friends. “Don’t tell me she’s made a pass at John. Or that he’s made a pass at her.”

“I’ve informed her it’s quite unnecessary,” he said. “She has, however, been the sole reason he’s chosen to stay at Baker Street. She convinced him to with her as his flat mate. He does not know the truth yet, but I imagine he will shortly after your return. I doubt this is a secret you can, or should, keep for long.”

“No, I don’t imagine we should,” he murmured. He waited for his brother to say more, but Mycroft began to concentrate on his food and he bit back a sigh. He knew he would get no more from his brother on any topic relating to why he was pulled out of his mission or what Elizabeth was up to until he was ready. But either way, he was now looking at his return to London with a slight sense of dread. He had the sinking suspicion that the reunions he was going to have with friends and his former wife were not going to go well at all.

If he was lucky, maybe he’d get through them without getting hit.


	2. Chapter 2

He had to suspect Anthea had picked out the suit waiting for him at Mycroft’s home. Not black, but a steel grey, tinged with a slight blueish hue in the right light. Not quite “surprise, I’m back from the dead” but also not quite “please be mourning for my death still,” either.

Also, the fabric would mop away blood rather easily, he was sure of that. He was also fairly sure either his best friend or his ex-wife was going to hit with the intent to cause damage. 

Maybe a black suit would have been better, but there was no help for it now.

He _almost_ wanted to see Molly at Barts first, but that was the coward's way. Molly _knew_ he was alive, having been part of the plan to fake his death. Whether Mycroft had kept her updated or not he didn’t do but he was fairly sure if he’d died Mycroft would have had the decency to inform her, so she had to know he was still alive somewhere in the world, which was more than John. Lestrade might be an option as well, because...well, because he probably wouldn’t receive a fist in the face for that homecoming, but no.

John and Elizabeth it was.

Scratch that. John and _Mary_.

He was going to stumble over that new name so much, he knew it. He was going to remember rambling conversations over cheap wine and crap low tar cigarettes where they had thoughts on whether they were alone in the universe, whether there really was a God, if there was such a thing as immaculate conception and he’d decided to show her what the Virgin Mary had been missing while she screamed his name at the top of her lungs when she came.

Come to think of it, maybe he’d just smirk every time he called her Mary, if she didn’t sock him in the face for it.

University had been a time where he’d hated everyone and everything but it had been his first real taste of freedom away from Mycroft and his parents and his Uncle Rudy, away from the miasma of _something_ that hung over his family like a dense shroud they couldn’t shake. The air was clearer when he wasn’t filling it with cigarette smoke and the haze of drugs. And he wanted to just lose himself in his world of books and say fuck all to the teachers. But Elizabeth...she’d caught his eye from day one, and try as he might to stop her, she wormed his way under his skin. He managed to stop the heavy drugs, sticking with the occasional hit of LSD and joints here and there, but mostly just having cheap wine and candy flavored vodka shots that Elizabeth would make in the flat they shared after their first year.

The marriage was impulsive but it felt right. He told no one, and even his brother in the government had no clue for _years_ because he stayed away from all of them. Said fuck off to his family and his life was school and Elizabeth and the occasional case when he could get someone to believe he knew what the bloody hell he was doing. The cases were better than school, but having Elizabeth by his side was what made it all work. Having a partner made it all worth it. They worked well together, thinking in sync. It was like they were two halves that fit.

And then Uncle Rudy died and the whole thing fell apart.

He came home to the flat and found is brother there with a sheaf of papers. Divorce papers. Said he wouldn’t get his share of the inheritance unless he signed them. Mycroft said not to worry, the amount of money he’d be getting would be more than enough to make him forget some university fling. It wouldn’t be hard to talk Elizabeth into it. There were people who had their eyes on her anyway.

He refused. It wasn’t like when they were children, when Mycroft was bigger in all the ways that mattered. Mycroft left the flat that evening with a broken jaw and Sherlock had bruised and bloodied knuckles and the divorce papers had blood on them. He was in the washroom cleaning up when Elizabeth came home and saw them. When he came out he could see something had changed in her eyes, and even when he explained it was all Mycroft’s fault, somehow she didn’t seem to believe him.

A week later he came back from class and there was her loopy signature on the papers and her things were gone.

That was the first time he’d overdosed since he was a teenager. He should have known his brother had taken the time to bug the flat when he woke up in the hospital.

He didn’t care, though. He refused rehab, went back to the flat and got the few things he cared about, moved out, finished the term and left for London as soon as he’d graduated, reinventing himself into Sherlock Holmes, Consulting Detective. The man who didn’t need anyone, because that was safer.

Of course, eventually, he gained friends. They started as colleagues...Lestrade and Molly, obviously. Mrs. Hudson started as a client. John was the first to be a friend. But in the end, they were all friends. He would die for any of them, kill for them if need be. The man he had been when he had been with Elizabeth had slowly come back, in some varied form. But now Elizabeth herself was here, and he wondered what type of man she was expecting: the young man she had loved? The high-functioning sociopath she had heard so much about? Something in between?

As Anthea slipped the new Belstaff on his shoulders and he adjusted it, finally feeling as close to his old self as he was able to, he knew the only way he would be able to tell would be to go back to Baker Street and take care of that reunion first...no matter how much he dreaded it.


	3. Chapter 3

He had the entire car ride to Baker Street to figure out what to say to whoever happened to be in the residence. That, of course, he wasn’t sure of; he knew his brother had the placed bugged to the hilt but he’d smugly denied him the names of who might be there when he arrived. If Mrs. Hudson went into cardiac arrest and couldn’t be revived because Mycroft had to be a smug git his older brother might soon find himself following her to the great beyond, of that Sherlock was _quite_ sure. 

Though, if Elizabeth had somehow managed to have the truth of it all gleaned from her, and he had the feeling she _had_ to know the truth to have picked his friends to keep safe, what with her background in the CIA, he imagined him showing up on the doorstep wouldn’t be quite the shock he’d initially thought it would be.

His mind drifted back to the long ago conversation during his university days. Mycroft had said people had had their eye on her, and she had ended up in the CIA. He had only known that much and only gleaned it recently through sheer coincidence. He’d rather hoped when he brought it up to his brother it might have given Mycroft just a moment of shock but no, apparently his brother had known he’d found out. But he wondered what all there was to the story. One did not simply _leave_ the CIA to galavant to England and set up a whole new life to babysit their ex-husband’s friends and colleagues, for lack of a better term, even if the threat was a world-renowned criminal mastermind who’d been manipulating him since they were children.

There had to be more to the story, and he was going to find the whole bloody thing out. They were going to be honest with each other. 

As he had been with her.

As she _should_ have been with him.

As that thought filled his head the car pulled to a stop and even in the dusky evening he could see the outline of the familiar blue door to his home and hear the sounds coming from Speedy’s. Even though much had changed over the years, some things never did, apparently. He opened the door to the car and as he looked up at the door to 221 Baker Street it opened and standing in the doorway was one person who looked so very familiar with small changes and one who looked so very different but achingly the same.

“The mustache is not very becoming, John,” he said, shutting the car door behind him without turning away from his best mate or his ex-wife. “The wardrobe changes are a vast improvement, though.”

“Your ex-wife has good taste,” John said with a small grin.

“She did agree to marry me,” he said in response.

John’s grin widened and he came out of the doorway, enveloping Sherlock in a warm hug. “I should beat the shite out of you,” he said.

Sherlock, taken aback for a moment, hugged him back. “You should, but you won’t.”

“Nah, I won’t,” he replied. He pulled back and gave Sherlock a more critical look, frowning. “Looks like someone else beat me to it.”

Sherlock nodded slowly, glad there were only a few signs of the beating and torture he took before his brother intervened above his neckline. He was not sure he wanted anyone to see the condition of his chest and back anytime soon, though he knew those wounds would need tending he would need help with. “Unfortunately.” He let go of John completely and moved towards the woman he had not seen in so long. Her hair was much shorter than it had been since he had last seen her, bleached blonde and clipped away from her face with barrettes. He knew his fingers were going to ache from not being able to run them through her brunette curls. “I suppose I should call you Mary now.”

“It would be best,” she said, giving him a smile. “It’s been a long while, William.”

“Sherlock,” he corrected.

“I see,” she said, her smile dimming. “Well, I suppose it’s fair. If I’m to be Mary I can’t call you William.” She pulled her shoulder away from the doorjamb. “We weren’t sure when your git of a brother would let you go but there’s takeaway. You’re still a fan of kung pow chicken and shrimp wontons, right?”

Sherlock nodded. It was strange that even after all this time, she still knew parts of him so well. “Yes.”

“Good. I’m glad there are still some things I know about you.” She tilted her head towards the inside. “Come on then. I imagine there’s a lot to talk about.” She headed inside then, leaving Sherlock and John alone for a moment.

“Are you alright with her being here?” John asked.

“I’ll manage,” Sherlock said. He nodded inside. “Best not to keep her waiting.” The two men headed inside and Sherlock shut the door behind him, wondering if he was ready for this after all.


	4. Chapter 4

The first meal together was no more awkward than he had expected it to be; when they weren’t eating they were catching each other up on what had happened in their lives in the two years of his absence. No more than that, though, he noticed; though Elizabeth seemed to know a great deal of what he and John had gone through from their first meeting, John said nothing about what she had gone through during that time that she had told him and she offered up no information herself. It seemed as if it was a topic that was being ignored for the moment.

The awkwardness came when they ran out of things to talk about and the silent periods became longer. After the third time, Sherlock bid the two of them a good night, heading to his bedroom. He was pleased to see nothing had changed, that it had been kept well tidied and dusted. When he was done re-familiarizing himself with his things, he went to his desk and the violin case that sat on top of it, fingering the case lightly. He had the urge to play, but it was not a strong urge and could be ignored for the time being for some time in his mind palace. He needed to think.

He sat on his floor, his back against the foot of the bed, and attempted to go into his mind palace. It had been harder to do as time had worn on during his time away; he hadn’t been sure why that was but he hoped being home would make it easier to return there. Instead, he found his mind drifting as his breathing slowed, and memories coming to him, memories he didn’t often think about.

_He was fiddling with his wedding ring again. He wondered why he didn’t just take the blasted thing off; it always got him questions from women who didn’t matter to him, who pestered him about his marital status. Like he would ever cheat--_

_He wasn’t married. It wouldn’t be cheating._

_Still, to him, it would be. Not that it would matter to **her** , because she had left him, but he would be with no other woman. Just her. He only wanted one wife, Elizabeth. No one else._

_“Your father’s ring?”_

_John’s voice jolted him out of his thoughts. “No,” he said. “Mine.” He glanced over at John and saw the look of shock on his face. It was to be expected. Who expected Sherlock Holmes, the world’s only consulting detective-slash-human robot, to have ever been in love? To have ever found a woman who would deign to marry him? “She left. Years ago.”_

_“You didn’t want her to,” John said._

_John may be blind to some things, but to others, he was quite astute. He shook his head. “She was made to.”_

_“And you want to find her?” he asked._

_He thought about the file he kept hidden, the very slim file where he kept any potential mention of Elizabeth. It was a pipe dream, really, to find her again. To see if...well, if there was anything left of what they'd had, if there was any way to fix what Mycroft had ruined. If they were even the same people._

_If they had ever been those people to begin with._

_“Yes,” he said very quietly, suddenly wanting to end this conversation. He slammed his hands down on the arms of the chair and then pushed himself up out f it. “Let’s go to the Yard and see if Lestrade has something for us. I need a case. I need something to help me not dwell on the past.”_

_And it was never brought up again._

His eyes snapped open and he tilted his head back onto the bed. He had forgotten he had been vulnerable like that to John before, had shared that about his past. He was sure Elizabeth had used that to her advantage, and Mycroft probably had as well if he had wanted information from her handlers and they had wanted information from him. It was all a secrets game, and perhaps it always had been. He deserved answers, but he had the feeling tonight was not when he would get them.

But soon, eventually, if they were not willingly given to him, he would begin demanding them.


	5. Chapter 5

It seemed for the first time in ages Sherlock slept soundly. There was no half-awake awareness to his sleep. It was deep and restful in a way it had not been for years, even after Mycroft had rescued him in Serbia and taken him to safety. There was something about being in his own home, being in his own bed, that made him feel _truly_ safe.

When he finally awoke, there was light streaming into the windows, and the clock on his nightstand said it was nearly noon. He had gone to sleep relatively early for him, at half past seven, so he had ended up sleeping for over sixteen hours. But he felt refreshed and rested, both things he had not felt in a long time.

He found his favourite dressing gown was on the back of the door and he slipped it on over the nightclothes he had worn. He had thought he would be in the flat by himself but he was surprised to hear the telly on and a burst of feminine laughter coming from the sitting room. He made his way out there and saw Elizabeth in his favourite chair, her feet tucked under her with a mug of something cradled in her hands. “Good morning, sleepyhead,” she said with a smile.

He grunted slightly and went to see if there as coffee. There was, and it was, surprisingly, still hot. “Where’s John?” he asked.

“At the surgery. It’s my day off so I volunteered to stay here and wait for Sleeping Beauty to wake up,” she said teasingly.

He looked at her from the kitchen, raising an eyebrow. “You actually do work there? It’s not just a cover?”

“I’m actually a nurse,” she said with a nod, rearranging her position to face him. “I’d studied to be one when I was in the CIA for a long term op and I rather liked it, so when I got out I got the proper schooling and made it my career.”

He nodded and then started to set up his coffee. Perhaps he would get his answers sooner than he had anticipated. “What did you do in the CIA?” he asked.

“I was an assassin,” she said simply.

His hand jerked as he poured the coffee. He knew she had agreed to help Moriarty at the pool and changed her mind, but to hear her say she was an assassin so nonchalantly was jarring. “What?” he said, turning to face her.

“I killed people, Sherlock,” she said. “Bad people. The type of people who can destroy countries and endanger the lives of millions or billions of people. And occasionally a few corrupt politicians or people who consider themselves outside the law.” She had a sip of her drink. “I was also a spy if that helps you swallow this down a bit better. I mean, that’s where the Intelligence part of Central Intelligence Agency comes in.”

“I thought the CIA didn’t kill people,” he said, regaining his composure.

“Officially,” she replied, stretching her feet onto the floor and then standing up. “Have you ever heard of a movie called ‘RED,’ Sherlock? RED stands for ‘Retired, Extremely Dangerous.’ There are not many CIA agents who do what I did who are alive long enough in reality to get RED status.” She took another sip of her coffee as she walked towards him. “I have it.”

He nodded. It appeared Elizabeth had changed quite a bit over the years. He wondered how much of the woman he had loved was left. “Why are you here?”

“A variety of reasons,” she said. “A, the CIA didn’t think you were dead, they knew my past history with you and they wanted intelligence. My ‘one last job’ that I was blackmailed into was supposed to be wooing John to find out what he knew. Then B, I realized John and your brother were on decent terms and I reached out to your brother and told him I’d been feeding him information on Moriarty for years, and he said he could provide me with everything my handlers would ever need to know if I left John out of the mess because he didn’t want your friends hurting anymore, which led to C, joint manuevs between the CIA and the British government for me to take up residence at Baker Street and integrate myself into their lives to keep your friends safe. That’s been my mission the last few years.”

“And I suppose now that I’m back you’ll just float away again,” he said, bitterness creeping into his tone.

“That was my ‘one last job,’ William,” Elizabeth said defensively. “ _Last_ job. I don’t answer to the CIA anymore. My life is _my_ life now.”

“Sherlock,” he said.

She shook her head. “You were never this much of an arse when we were married,” she replied, putting her coffee mug on the counter with some force.

“Well, you didn’t give our marriage a chance!” he said, raising his voice.

“You had divorce papers waiting for me when I got home!” she yelled.

“That was my brother’s doing!” he yelled back. “I’d already told him to shove the inheritance up his arse but you didn’t believe me!”

“How did I know it wasn’t a mistake? That you wouldn’t change your mind later?” she said.

Sherlock closed the gap between them, pulling Elizabeth against him and bending down, pressing his lips against hers. He was never one to do anything like this in any other circumstance, really. He nearly always kept his cool and never let his passions get the best of him except around her. When he was around her she just brought this side of him out. But after a moment she was wrapping her arms around his neck and kissing him back like the years hadn’t gone by and it was the two of them in their dingy flat in university and there wasn’t all this baggage between them. 

And then they had to pull apart, to catch their breaths, and he pressed his forehead against hers, his eyes shut but his grip tight. “It’s been years, Elizabeth, and I still want to snog you like that every chance I get,” he said.

She undid her arms from around his neck and then framed his face. “Everything is different now, though,” she said. “We aren’t who we were in uni.”

“We’ll sort it out later,” he replied. “Just promise you’ll stay this time.” She didn’t speak, simply nodding her head against his before kissing him this time, and he knew that there would need to be more conversations later, but for now, this was more than enough.


End file.
